ipodderx-rs/CLAUDE.md

Working on ipodderx-rs

Notes for whoever picks this up next. Read docs/architecture.md for how the thing is built; this file is about working on it without repeating mistakes that have already been made here.

Where things are

The live install on this machine:

Binary	/config/.cargo/bin/ipx
Config	/config/.config/ipx/config.toml
Database	/config/.local/share/ipx/state.db
Downloads	/mnt/user/audio/ipx
Web UI	0.0.0.0:8099, also ipodderx.sdf1.net via a Cloudflare tunnel

Deploying a change is: build, stop, copy, start.

cargo build --release
pkill -x ipx; sleep 2
cp target/release/ipx /config/.cargo/bin/ipx
setsid nohup /config/.cargo/bin/ipx --config /config/.config/ipx/config.toml daemon \
  >/tmp/ipx.log 2>&1 </dev/null &

pkill -x ipx, never pkill -f ipx. -f matches the shell running the command and kills the session (exit 144). This has happened more than once.

The daemon is not supervised: it will not survive a reboot. contrib/ has a systemd unit nobody has installed.

Before you touch the page

web/index.html is include_str!d into the binary, so every page change needs a rebuild before it is visible. It is one file: markup, CSS and script.

After any edit to it:

node tests/page-smoke.js

That loads the script against a stub DOM and checks every selector it wires at load actually exists. It exists because a patch once anchored on a deleted function, String.replace silently matched nothing, and the whole UI died with a ReferenceError while every server-side test passed.

Patching that file by guessing an anchor string has failed repeatedly. Read the exact block first (sed -n 'START,ENDp'), match it verbatim, and assert the replacement happened rather than hoping.

Tests

cargo test                # ~51 tests: parsing, filters, retention, schedules, SQL, per-user state
node tests/page-smoke.js
npx playwright test       # 16 browser tests against a real daemon on fixture feeds

Things about the browser suite that have cost time:

• It starts its own daemon and database under /tmp/ipx-ui-test, wiped once per run. Playwright re-imports the config in every worker, so prepare() guards on TEST_WORKER_INDEX — without that guard a worker deleted the database out from under the running daemon, which then kept serving from the unlinked inode while everything else saw an empty file.
• Tests share that daemon and run in order. A test that opens an item marks it read and changes what later tests see. Write assertions that do not depend on what ran before, or normalise the state first.
• Fixture feeds must not share an enclosure URL, because enclosures.url is globally unique and whichever feed is scanned first claims it.
• webServer starts before globalSetup, which is why the fixture config is written at config-load time instead.

Non-trivial logic leaves one runnable check behind. Pure functions (merge_policy, pick, matches_keywords, parse_interval) are the easiest place to put it.

Things that are true and easy to get wrong

• enclosures.url is globally UNIQUE. It is the dedupe key and the reason one file serves every subscriber. Two feeds publishing the same URL means only the first one scanned shows it.
• entries.read, entries.flagged and entries.position are dead columns. Read state lives in entry_state per user. Two bugs have already come from queries still reading the old ones (retention, and the entry pruner) — grep before adding a third.
• The catalogue is config.toml; the subscriptions are in the database. A feed exists once; subscriptions(user_id, feed_id) says who wants it and with what settings. OPML children are derived and never written to config.
• One fetch serves everyone, so scan policy is a union of subscribers' wants (merge_policy). Anyone wanting an item is enough to fetch it.
• The UI hiding a control is not enforcement. Admin-only actions check user.is_admin in the handler and return 403.
• A tokio::select! only races its branches at the point of selection. A long download has to watch the shutdown channel itself; the daemon ignored SIGTERM for exactly this reason.
• Only one daemon per socket. Removing the socket file defeats the guard and you get two daemons fighting over the database, with the stale one still holding the port.
• /api/settings answering 200 does not mean the worker is alive — it is a different task. Probe the control socket (ipx status) to check that.

House style

Comments explain why, not what. If a line looks odd, the comment says what went wrong without it. No emoji, no exclamation marks, no "obviously". Prose in the UI and docs is plain English and addressed to the person using it.

Every change gets an entry at the top of CHANGELOG.md, dated, saying what landed and what was wrong before. That record has been more useful than the git log more than once.

Deliberate simplifications get a ponytail: comment naming the ceiling and the upgrade path, e.g. // ponytail: global connection mutex, move to a pool if feed count makes it contend.

Known gaps

• No user administration in the web UI; ipx user on the box only.
• Cloudflare's Cf-Access-Jwt-Assertion is not verified — ipx trusts the hop plus trusted_proxies (documented in docs/sso.md).
• The Docker image predates multi-user; docker compose build before relying on it.
• Downloads land root-owned; Unraid shares want 99:100.
• A feed's <description> subtitle is dropped whenever content:encoded exists, which loses Substack-style subtitles.